This chapter describes international reports where the goal is to present comparisons of student ability to read with comprehension under a range of academic tasks; addresses some of the changes in reading proficiency, performance, and achievement over time as evidenced in these reports with particular attention to Mexico and Latin America; and provides a critique of findings with attention to achievement "gaps" in reading. The international reports addressed in the chapter target adolescents. Throughout the world, after a century of attention to research on child development, there is growing use of data to investigate adolescent ability to read with critical thinking— analytically and interpretively— for real-world applications. The reports of international literacy and reading per se cited in the chapter focus on single countries in the world but do not address the current-day adolescent binationalism, bilingualism, and cross-cultural mobility, more prevalent at this time than ever before, that may influence reading habits, practices, and achievement.